Page 1833 of 3115
EM6325
A05592
EM6327
EM0580
EM-46
- ENGINE MECHANICALCYLINDER HEAD
1619 Author: Date:
2004 LAND CRUISER (RM1071U)
5. CLEAN CYLINDER HEAD
Using a soft brush and solvent, thoroughly clean the cylinder
head.
6. INSPECT FOR FLATNESS
Using a precision straight edge and a feeler gauge, measure
the surfaces contacting the cylinder block and the manifolds for
a warp.
Maximum warpage:
0.10 mm (0.0039 in.)
If the warp is greater than maximum, replace the cylinder head.
7. INSPECT FOR CRACKS
Using a dye penetrate, check the combustion chamber, the in-
take ports, the exhaust ports and the cylinder head surface for
cracks.
If there is a crack, replace the cylinder head.
8. CLEAN VALVES
(a) Using a gasket scraper, chip off any carbon from the valve
head.
(b) Using a wire brush, thoroughly clean the valve.
Page 1834 of 3115

P21862
Z00052
Z00054
- ENGINE MECHANICALCYLINDER HEAD
EM-47
1620 Author: Date:
2004 LAND CRUISER (RM1071U)
9. INSPECT VALVE STEMS AND GUIDE BUSHINGS
(a) Using a caliper gauge, measure the inside diameter of the
guide bushing.
Bushing inside diameter:
5.510 - 5.530 mm (0.2169 - 0.2177 in.)
(b) Using a micrometer, measure the diameter of the valve
stem.
Valve stem diameter:
Intake
5.470 - 5.485 mm (0.2154 - 0.2159 in.)
Exhaust
5.465 - 5.480 mm (0.2152 - 0.2157 in.)
(c) Subtract the valve stem diameter measurement from the
guide bushing inside diameter measurement.
Standard oil clearance:
Intake
0.025 - 0.060 mm (0.0010 - 0.0024 in.)
Exhaust
0.030 - 0.065 mm (0.0012 - 0.0026 in.)
Maximum oil clearance:
Intake
0.08 mm (0.0031 in.)
Exhaust
0.10 mm (0.0039 in.)
If the clearance is greater than the maximum, replace the valve
and the guide bushing. (See Page EM-55)
10. INSPECT AND GRIND VALVES
(a) Grind the valve enough to remove pits and carbon.
(b) Check that the valve is ground to the correct valve face
angle.
Valve face angle:
44.5°
Page 1835 of 3115

EM0181
Margin Thickness
EM2534
Overall Length
EM0255
EM6330
45° Carbide Cutter EM-48
- ENGINE MECHANICALCYLINDER HEAD
1621 Author: Date:
2004 LAND CRUISER (RM1071U)
(c) Check the valve head margin thickness.
Standard margin thickness:
IN 1.25 mm (0.049 in.)
EX 1.40 mm (0.055 in.)
Minimum margin thickness:
0.5 mm (0.020 in.)
If the margin thickness is less than the minimum, replace the
valve.
(d) Check the valve overall length.
Standard overall length:
Intake: 95.05 mm (3.7421 in.)
Exhaust: 95.10 mm (3.7441 in.)
Minimum overall length:
Intake: 94.55 mm (3.7224 in.)
Exhaust: 94.60 mm (3.7244 in.)
If the overall length is less than the minimum, replace the valve.
(e) Check the surface of the valve stem tip for wear.
If the valve stem tip is worn, resurface the tip with a grinder or
replace the valve.
NOTICE:
Do not grind off to below the minimum.
11. INSPECT AND CLEAN VALVE SEATS
(a) Using a 45° carbide cutter, resurface the valve seats. Re-
move just enough metal to clean the seats.
Page 1836 of 3115

Z00055
Width
Z03988
45°30°
1.0 - 1.4 mm
Z03989
60°45°
1.0 - 1.4 mm
EM6331
EM0988
Deviation
- ENGINE MECHANICALCYLINDER HEAD
EM-49
1622 Author: Date:
2004 LAND CRUISER (RM1071U)
(b) Check the valve seating position.
Apply a light coat of prussian blue (or white lead) to the
valve face. Lightly press the valve against the seat. Do not
rotate valve.
(c) Check the valve face and seat for the following:
If blue appears 360° around the face, the valve is
concentric. If not, replace the valve.
If blue appears 360° around the valve seat, the
guide and face are concentric. If not, resurface the
seat.
Check that the seat contact is in the middle of the
valve face with the following width:
1.0 - 1.4 mm (0.039 - 0.055 in.)
If not, correct the valve seats as follows:
If the seating is too high on the valve face, use 30°
and 45° cutters to correct the seat.
If the seating is too low on the valve face, use 60°
and 45° cutters to correct the seat.
(d) Hand-lap the valve and valve seat with an abrasive com-
pound.
(e) After hand-lapping, clean the valve and valve seat.
12. INSPECT VALVE SPRINGS
(a) Using a steel square, measure the deviation of the valve
spring.
Maximum deviation:
2.0 mm (0.079 in.)
If the deviation is greater than the maximum, replace the valve
spring.
Page 1837 of 3115

EM0801
EM0281
A05912
EM2011
EM-50
- ENGINE MECHANICALCYLINDER HEAD
1623 Author: Date:
2004 LAND CRUISER (RM1071U)
(b) Using vernier calipers, measure the free length of the
valve spring.
Free length:
54.1 mm (2.130 in.)
If the free length is not as specified, replace the valve spring.
(c) Using a spring tester, measure the tension of the valve
spring at the installed length.
Installed tension:
204 - 226 N (20.8 - 23.0 kgf, 45.9 - 50.7 lbf)
at 35.0 mm (1.378 in.)
If the installed tension is not as specified, replace the valve
spring.
13. INSPECT CAMSHAFT FOR RUNOUT
(a) Place the camshaft on V-blocks.
(b) Using a dial indicator, measure the circle runout at the
center journal.
Maximum circle runout:
0.08 mm (0.0031 in.)
If the circle runout is greater than the maximum, replace the
camshaft.
14. INSPECT CAM LOBES
Using a micrometer, measure the cam lobe height.
Standard cam lobe height:
Intake:
41.94 - 42.04 mm (1.6512 - 1.6551 in.)
Exhaust:
41.96 - 42.06 mm (1.6520 - 1.6559 in.)
Minimum cam lobe height:
Intake:
41.79 mm (1.6453 in.)
Exhaust:
41.81 mm (1.6461 in.)
If the cam lobe height is less than the minimum, replace the
camshaft.
Page 1838 of 3115

A05519
EM3322
A05520
Plastigage
A05522
- ENGINE MECHANICALCYLINDER HEAD
EM-51
1624 Author: Date:
2004 LAND CRUISER (RM1071U)
15. INSPECT CAMSHAFT JOURNALS
Using a micrometer, measure the journal diameter.
Journal diameter:
26.954 - 26.970 mm (1.0612 - 1.0618 in.)
If the journal diameter is not as specified, check the oil clear-
ance.
16. INSPECT CAMSHAFT GEAR SPRING
Using vernier calipers, measure the free distance between the
spring ends.
Free distance:
18.2 - 18.8 mm (0.712 - 0.740 in.)
If the free distance is not as specified, replace the gear spring.
17. INSPECT CAMSHAFT BEARINGS
Check that bearings for flaking and scoring.
If the bearings are damaged, replace the bearing caps and cyl-
inder head as a set.
18. INSPECT CAMSHAFT JOURNAL OIL CLEARANCE
(a) Clean the bearing caps and the camshaft journals.
(b) Place the camshafts on the cylinder head.
(c) Lay a strip of plastigage across each of the camshaft jour-
nals.
(d) Install the bearing caps.
(See page EM-59)
Torque: 16 N´m (160 kgf´cm, 12 ft´lbf)
NOTICE:
Do not turn the camshaft.
(e) Remove the bearing caps.
Page 1839 of 3115

A05521
A05523
A05524
EM-52
- ENGINE MECHANICALCYLINDER HEAD
1625 Author: Date:
2004 LAND CRUISER (RM1071U)
(f) Measure the Plastigage at its widest point.
Maximum oil clearance:
0.10 mm (0.0039 in.)
If the oil clearance is greater than the maximum, replace the
camshaft. If necessary, replace the bearing caps and cylinder
head as a set.
(g) Completely remove the plastigage.
(h) Remove the camshafts.
19. INSPECT CAMSHAFT THRUST CLEARANCE
(a) Install the camshaft.
(See page EM-59)
(b) Using a dial indicator, measure the thrust clearance as
moving the camshaft back and forth.
Standard thrust clearance:
Intake
0.040 - 0.090 mm (0.0016 - 0.0035 in.)
Exhaust
0.040 - 0.085 mm (0.0016 - 0.0033 in.)
Maximum thrust clearance:
0.12 mm (0.0047 in.)
If the thrust clearance is greater than the maximum, replace the
camshaft. If necessary, replace the bearing caps and cylinder
head as a set.
(c) Remove the camshafts.
20. INSPECT CAMSHAFT GEAR BACKLASH
(a) Install the camshafts without installing the exhaust cam
sub-gear and the front bearing cap.
(See page EM-59)
(b) Using a dial indicator, measure the backlash.
Standard backlash:
0.020 - 0.200 mm (0.0008 - 0.0079 in.)
Maximum backlash:
0.30 mm (0.0188 in.)
If the backlash is greater than the maximum, replace the cam-
shafts.
(c) Remove the camshafts.
Page 1840 of 3115

A03209
A03201
12.3 - 12.7 mm
A05499
- ENGINE MECHANICALCYLINDER HEAD
EM-53
1626 Author: Date:
2004 LAND CRUISER (RM1071U)
21. INSPECT VALVE LIFTERS AND LIFTER BORES
(a) Using a caliper gauge, measure the lifter bore diameter
of the cylinder head.
Lifter bore diameter:
31.000 - 31.016 mm (1.2205 - 1.2211 in.)
(b) Using a micrometer, measure the lifter diameter at the
valve lifter center line, 12.3 - 12.7 mm (0.484 - 0.500 in.)
from the valve lifter head.
Lifter diameter:
30.966 - 30.976 mm (1.2191 - 1.2195 in.)
(c) Subtract the lifter diameter from the lifter bore diameter.
Standard oil clearance:
0.024 - 0.050 mm (0.0009 - 0.0020 in.)
Maximum oil clearance:
0.07 mm (0.0028 in.)
If the oil clearance is greater than the maximum, replace the lift-
er. If necessary, replace the cylinder head.
22. INSPECT INTAKE MANIFOLD
(a) Upper intake manifold:
Using a precision straight edge and a feeler gauge, mea-
sure the surface contacting of the lower intake manifold
for a warp.
Maximum warpage: 0.15 mm (0.0059 in.)
If the warp is greater than the maximum, replace the upper in-
take manifold.